Rhodiola is one of the herbs that have been found effective in the treatment of depression. Although, it is primarily known as an adaptogen in alternative medicine, the medicinal benefits of rhodiola can also help improve mood and relieve depressive symptoms. How effective is rhodiola as an antidepressant? How does it work and is it safe? Read on to find out.

Rhodiola (Rhodiola rosea) is a perennial herb native to the arctic regions especially the cold regions of China, Russia and other parts of Asia and Europe. It is very common in the wild and grows best in the high altitude areas of these cold regions. In these regions, rhodiola is also known by some other names such as arctic root, rose root, and golden root.

The medicinal benefits of rhodiola root are well-known in Chinese and Russian traditional medicine. It has a long history (dating back to thousands of years) in these cultures as a remedy for various stress-related conditions.

Rhodiola is considered an adaptogen because of its ability to relieve and prevent stress.

An adaptogen increases the body’s resistance (in non-specific ways) to stress triggered by either physiological or psychological factors. Many studies have found that rhodiola has the ability to improve work performance, insomnia, headache, fatigue and depression.

There are six distinct groups of phytochemicals in rhodiola. These groups of phytochemicals are listed in the table below.

Major Phytochemicals of Rhodiola

Phenylpropanoids: rosavin, rosin, rosarin;

Phenylethanol derivatives: salidroside (rhodioloside), tyrosol;

Flavonoids: rodiolin, rodionin, rodiosin, acetylrodalgin, tricin;

Monoterpenes: rosiridol, rosaridin;

Triterpenes: daucosterol, beta-sitosterol;

Phenolic acids: chlorogenic and hydroxycinnamic, gallic acids.

It was previously thought that the phenylethanol derivative, salidroside, was the only bioactive chemical responsible for rhodiola’s therapeutic effects. Recent studies have however established that salidroside and the phenylpropanoids (rosin, rosavin, rosarin and rosaridin) are the main bioactive pharmacological components of rhodiola.

Rosavins is the general term used to refer to all the phenylpropanoids compound present in rhodiola.

Before the discovery of the rosavins, other species of Rhodiola genus were used as herbal medicines in place of Rhodiola rosea. It was later found that only the Rhodiola rosea species contains the essential therapeutic compounds, rosavins.

Due to a better understanding of rhodiola’s phytochemicals, rhodiola root extracts are now standardized to contain at least 3% rosavins and 0.8 - 1% salidroside.

Rosavins and salidroside are known to naturally occur in the ratio of 3:1 in R. rosea root.

When you experience changes in mood, especially during depression, the concentrations and/or activities of monoamine neurotransmitters in the brain are reduced.

Neurotransmitters are responsible for transmitting nerve impulses between neurons. Hence, any reduction in their activities interferes with the extensive neuronal communication dependent on these brain chemicals.

Serotonin (also known as 5-HT), for example, is a monoamine neurotransmitter that is involved in the regulation of mood, appetite and sleep. This brain chemical is believed to play a major role in the feelings of well-being and happiness.

In response to low concentration and activity of serotonin in the brain, there will be a dip in mood. This is often what characterizes depression.

Dopamine, on the other hand, contributes to feelings of motivation, reward and mood as well as sleep and attention. Recent studies have shown high levels of dopamine activity in individuals who are outgoing or individuals of extroverted personalities.

Monoamine oxidases are the enzymes responsible for breaking down monoamine neurotransmitters. The major examples of monoamine neurotransmitters are dopamine, serotonin and norepinephrine.

Therefore, to relieve depression and maintain a balanced mental state, the neurotransmitters in the brain need to be restored to normal levels. This can be done either by increase their syntheses or by preventing their breakdown (monoamine oxidase inhibitors).

Rhodiola root extract improves the activities of dopamine and serotonin in the brain by blocking the enzymatic breakdown of these brain chemicals by monoamine oxidases.

In addition, Rhodiola root extract promotes the transport of dopamine and serotonin precursors into the brain by increasing the permeability of the blood brain barrier to these precursors.

Some studies have shown that serotonin levels in the brain can be boosted by as much as 30% with the use of rhodiola root extract. This increase is due to the combination of the two mechanisms stated above.

Rhodiola extract is also known to reduce stress. As an adaptogen, it helps the body adapt to environmental, chemical and physical stressors.

The body responds to stress by releasing a hormone known as cortisol. The adaptogenic effects of rhodiola extract inhibits the release of this stress hormone. This anti-stress action of rhodiola reduces the chances of stress-induced depression.

Lastly, rhodiola extract has the ability to protect human cortical neurons from destruction by hydrogen peroxide radicals and glutamates. The salidroside component of rhodiola extract is believed to be responsible for this neuroprotective action.

Rhodiola extracts are derived from its root. The extracts are available in form of tablets, capsules and tinctures.

The suggested daily dose of standardized rhodiola extract is between 200 mg and 600 mg. The daily intake can be divided into 2 capsules or tablets. The first dose should be taken in the morning before breakfast and then later in the afternoon just before lunch.

Due to the stimulating action of rhodiola root extract, it can cause insomnia when taken at night.

For the body to gradually develop tolerance to the side effects of rhodiola extract, patients are advised to start from a low dose of 100 mg. Then the dose can gradually be increased with time to as much as 600 mg.

The reaction and response of the body to increased doses should be noted so help determine the appropriate dosage of the herb.

Rhodiola extract is generally considered safe. Unlike other stimulants like caffeine and nicotine, it is non-addictive.

Although mild side effects such as nausea, jitters, anxiety, agitation, hypersalivation, restlessness, and insomnia have been reported, they are thought to be as the result of combining rhodiola extract with other herbs or medications.

For example, consuming a caffeinated beverage such as coffee after taking rhodiola extract can result in over activity and anxiety. Other sources of stimulants such as nicotine gum, cigarettes and teas can also cause these effects when combined with rhodiola.

In addition, rhodiola extract should not be taken after or before a sugary meal (candy, cakes or sweets) to avoid jitters. A spike in the blood’s sugar coupled with the stimulant effect of rhodiola extract can produce this feeling.

Since rhodiola works by promoting the activities of serotonin in the brain, combining the herb with other antidepressants such as SSRIs (selective serotonin reuptake inhibitors) can lead to a fatal condition known as serotonin syndrome.

The safety of this herb has not been well demonstrated in pregnant and lactating women. It should therefore be avoided by these groups of patients until proper studies are available to confirm its safety.

A 2009 study published in the journal, Phytomedicine, investigated the effect of Rhodiola rosea extract on serotonin levels in the brains of depressed rats.

Seventy depressed rats were divided into seven groups with 10 rats in each group:

normal control group

untreated depressive rat model group

negative control group

positive control group

low dosage Rhodiola rosea extract (1.5 g/kg) group

medium dosage Rhodiola rosea extract (3 g/kg) group

high dosage Rhodiola rosea extract (6 g/kg) group.

After a period of 3 weeks, the serotonin levels in the brains of the rats were examined by high performance liquid chromatography, a technique for detecting small levels of chemical compounds.

The results of the study showed that the serotonin levels of rats in the three groups given Rhodiola rosea extracts were restored to normal. This result concluded that Rhodiola rosea extract is capable of improving serotonin level in the brains of depressed rats.

A similar study published in the journal, Phytotherapy Research, in 2007 investigated the antidepressant effect of Rhodiola rosea extract in rats.

A hydroalcohol extract of Rhodiola rosea was given to rats at doses of 10, 15 and 20 mg/kg. The study made use of predictive behavioral tests and animal models to assess antidepressant activities in the rats.

The result of the study showed significant antidepressant activities in the behavioral test and animal models of depression. This suggests that hydroalcohol extract of Rhodiola rosea has significant antidepressant effects.

A 2002 study published in the journal, Herbalgram, examined the effectiveness of Rhodiola rosea extract in 150 depressed patients.

The participants in this study were given Rhodiola rose extracts for a period of one month.

The results of the study showed significant improvement and full remission of clinical manifestations of depression in two thirds of the patients. No adverse effects were recorded in the study.

Another 2007 study published in the Nordic Journal of Psychiatry examined the effectiveness of Rhodiola rosea extract in individuals diagnosed with mild to moderate depression. In this study, 89 volunteers between the ages of 18 and 70 participated. They were divided into three groups.

The first group of 29 participants were given 680 mg of Rhodiola rosea extract. Another group of 31 participants were given 340 mg of Rhodiola rosea extract while the remaining 29 participants were given placebo for a period of six weeks.

Severity of depression was assessed based on scores from the Beck Depression Inventory and Hamilton Rating Scale for Depression (HAMD) questionnaires.

After the 6-week duration of the study, significant improvements in depression, emotional instability and insomnia were demonstrated in the two groups given different doses of Rhodiola rosea extract compared to the placebo group.